Some people avoid risk while others will roll the dice with wealth, health, and safety. Is it just personality? Media influence?

Researchers led by Ifat Levy, assistant professor in comparative medicine and neurobiology at Yale School of Medicine believe that the volume of the parietal cortex in the brain can predict where people fall on the risk-taking spectrum. 

The team found that those with larger volume in a particular part of the parietal cortex were willing to take more risks than those with less volume in this part of the brain. They may be a little too free with correlation and causation because lots of cognitive and personality traits are also correlated to images of brain structure. Linking brain structure to economic preferences seems to be as crazy as linking it to voting preference but Levy and colleagues sought to examine this question in their study. 

Study participants included young adult men and women from the northeastern United States. Participants made a series of choices between monetary lotteries that varied in their degree of risk, and the research team conducted standard anatomical MRI brain scans. The results were first obtained in a group of 28 participants, and then confirmed in a second, independent, group of 33 participants.

"Based on our findings, we could, in principle, use millions of existing medical brains scans to assess risk attitudes in populations," said Levy. "It could also help us explain differences in risk attitudes based in part on structural brain differences."

Levy affirms that the results do not speak to causality. "We don't know if structural changes lead to behavioral changes or vice-versa," she said.

Levy and her team had previously shown that risk aversion increases as people age, and we scientists also know that the cortex thins substantially with age. "It could be that this thinning explains the behavioral changes; we are now testing that possibility," said Levy, who also notes that more studies in wider populations are needed.